Method for catalytically converting residual oils

ABSTRACT

A process for converting residual oil comprising vacuum bottoms in the presence of a cracking catalyst of high surface area and comprising an ultrastable zeolite is described. More particularly, a conversion process particularly contributing to producing cycle oil and gasoline boiling range products with reduced carbon deposition in combination with a relatively high regeneration temperature operation of at least 1350° F. and above, and a short contact time riser hydrocarbon conversion operation contributing to reducing slurry oil product in favor of lower boiling products is described. A fluid cracking catalyst comprising a special ultrastable crystalline zeolite of high silica to alumina ratio provides hydrothermal stability of acceptable tolerance in the environment employed.

.Iadd.This is a continuation of application Ser. No. 798,031, filed11-13-85, now abandoned, which is a Reissue application Ser. No.06/324,450 now U.S. Pat. No. 4,415,438. .Iaddend.

BACKGROUND OF THE INVENTION

Fluid catalytic cracking has undergone many changes since its inceptionin the early 1940's. One of the recent process advances in fluidcatalytic cracking has been the advent of zeolite catalysts usage whichhas prompted many process design modifications. Feed-stocks, however,have changed very little up to recent years, being comprised of mostlyatmospheric and vacuum gas oils. However, with the economic need of theindustry to process poorer quality crude oils, and a need at the sametime to maintain high gasoline yields, the ability to effect conversionof poor quality feed stocks in a FCCU process is now of significantimportance.

The present invention is directed to extending the processed boilingrange of crude oil feedstocks to include substantially all of theatmospheric bottoms, a residual or reduced crude portion thereof andcomprising vacuum tower bottoms by catalytically cracking such materialsin a selective process more fully discussed below that converts a highlyatomized-vaporized mixture of the feed components at a relatively hightemperature with an ultrastable crystalline zeolite catalyst hereinidentified.

U.S. Pat. No. 4,287,048 particularly identifies an ultrastable "Y" typecrystalline zeolite and its method of preparation in the followingmanner. "Stabilized" or ultrastable Y-type zeolites are well-known. Theyare described, for example, in U.S. Pat. Nos. 3,293,192 and 3,402,996and the publication Society of Chemical Engineering (London) MonographMolecular Sieves, page 186 (1968) by C. V. McDaniel and P. K. Maher, theteachings of which are hereby incorporated by reference. In general,"ultrastable" refers to a Y-type zeolite which is highly resistant todegradation of crystallinity by high temperature and steam treatment andis characterized by a R₂ O content (wherein R is Na, K or any otheralkali metal ion) of less than 4 weight percent, preferably less than 1weight percent and a unit cell size less than 24.5 Angstroms and asilica to alumina mole ratio in the range of 3.5 to 7 or higher. Theultrastable form of Y-type zeolite is obtained primarily by asubstantial reduction of the alkali metal ions and the unit cell sizereduction. The ultrastable zeolite is identified both by the smallerunit cell and the low alkali metal content in the crystal structure.

As is generally known, the ultrastable form of the Y-type zeolite can beprepared by successively base exchanging a Y-type zeolite with anaqueous solution of an ammonium salt, such as ammonium nitrate, untilthe alkali metal content of the Y-type zeolite is reduced to less than 4weight percent. The base exchanged zeolite is then calcined at atemperature of 1000° F. to 1500° F., for up to several hours, cooled andthereafter again successively base exchanged with an aqueous solution ofan ammonium salt until the alkali metal content is reduced to less than1 weight percent, followed by washing and calcination again at atemperature of 1000° to 1500° F. to produce an ultrastable zeolite Y.The sequence of ion exchange and heat treatment results in thesubstantial reduction of the alkali metal content of the originalzeolite and results in a unit cell shrinkage which is believed to leadto the ultra high stability of the resulting Y-type zeolite. Theparticle size of the zeolites is usually in the range of 0.1 to 10microns, more particularly in the range of 0.5 to 3 microns.

Suitable amounts of the ultrastable Y-type zeolite in the catalyst ofthe present invention include from about 10 to about 80 weight percent,preferably from about 30 to about 50 weight percent, based on the totalcatalyst.

SUMMARY OF THE INVENTION

The catalytic cracking or conversion of heavy oil feeds comprisingatmospheric tower bottoms vacuum gas oils plus resid, residual oil,reduced crudes, and topped crudes, shale oil, coal liquefaction oilproducts and tar sands oil products all of which comprise componentsboiling above 1000° F. or 1050° F. are best catalytically converted in ahighly vaporized-atomized contact phase of the oil feed with selectfluid catalyst particles of a composition herein identified. The heatnecessary to substantially completely vaporize-atomize all of the highboiling oil feed is contributed by a relatively high regeneratortemperature operation of at least about 1350° F. and preferably above1400° F. completed in the substantial absence of hydro-thermal damage tothe catalyst. The more conventional zeolite cracking catalystscomprising relatively large amounts of one or more rare-earth exchangedfaujasite zeolites are susceptible to considerable hydro-thermaldeactivation under high temperature regeneration conditions above about1400° F. and required to remove relatively large amounts ofhydrocarbonaceous materials deposited during residual oil crackingoperations.

It is observed through commercial experience of catalytically crackingheavier and heavier feed stocks that there is a marked tendency for theregenerator temperature to rise to higher levels as the quality of thefeed stock deteriorates. (Heavier and lower quality feed stocks for thepurposes of this discussion refers to the inclusion of high boilingresidual oils of high Conradson carbon in the feed).

It is also observed that if the regenerator temperature is restrained bymeans not usually employed in conventional gas oil cracking such asproviding steam coils in the regenerator, external catalyst coolersand/or other means employed by some operators, the selectivity of thehydrocarbon conversion reaction shifts in the direction of producingundesirable large amounts of coke and liquid products referred to as"cycle oils". Cycle oils are liquid products comprising large quantitiesof condensed ring aromatics. The condensed ring aromatics are two,three, four and larger six carbon member rings. The cycle oilscomprising largely two member rings referred to as light cycle oils(LCO) are commercially marketable as middle distillate. Cycle oilscomprising largely three and a greater number of condensed rings such asfound in some heavy cycle oils and particularly slurry oils are of lowcommercial worth and are usually only marketed as bunker fuel.

On the other hand, it is observed in commercial catalytic cracking ofthe heavier feed stocks comprising residual oils that if the tendencyfor the regenerator temperature to rise to a higher level is notrestrained then the undesirable reaction to selectivity described abovedoes not occur. That is, at higher regenerator temperatures and attemperatures generally above those employed commercially for gas oilcracking, above 1350° F., coke production is equal to or lower than thatobserved in conventional gas oil cracking, and the production ofcondensed ring aromatics larger than two member rings is discouraged.

It is observed in a study of catalysts suitable for converting highboiling residual oils, that contrary to many of the teachings in theprior art, a high surface area crystalline zeolite such as anultrastable crystalline zeolite, commercially identified by DavisonChemical Co. as Z-14US, is a highly stable and effective conversioncatalyst at the high regeneration temperatures required when processinghigh boiling residual oil type feeds despite its relatively low freshcatalyst activity. More importantly, when the processing concepts ofthis invention are pursued, it is further observed that the high surfacearea ultrastable crystalline zeolite contributes to a significantreduction in deposition of hydrocarbonaceous material, improves lightcycle product yield at the expense of heavier cycle oils and provides aproduct selectivity generally richer in gasoline and gasoline formingcomponents than is achieved with a more conventional rare-earthexchanged zeolite such as CREY at comparable fresh feed conversionlevels.

It is further observed that the commercially available high activityzeolitic catalysts comprising rare earth exchanged zeolites, experiencesa serious surface area decline. This surface area decline is viewed tobe due to hydro-thermal instability under the conditions of thepreferred unit operating mode. As the surface area progressively decays,it is further observed that product selectivity shifts in the directionof increased heavy cycle oil production and particularly cycle oils ofring structures greater than 2 member rings, increased gas productioncomprising H₂, C₁ 's and C₂ 's and more importantly a reduced gasolineproduction.

The outer or exterior surface such as provided by a high surface areaultrastable zeolite is found to be very effective in providingaccessible and available active cracking sites to affect the nowexperienced substantial molecular weight reduction of high molecularweight components in a slurry oil to more desirable lower molecularweight components. The hydrothermal stability of an ultrastablecrystalline zeolite catalyst prepared as herein identified and brieflydiscussed is found to be superior to that of a rare-earth exchanged "Y"faujasite referred to as CREY and used to form catalyst particles forcracking hydrocarbon feed materials. The ultrastable zeolite containingcatalysts maintain significantly higher surface areas equilibriumcatalysts at high regeneration temperatures than obtained with a CREYcatalyst. A matrix or base material with a relatively high amorphoussurface area which provides active cracking sites may be employed withthe ultrastable zeolite in lieu of more catalytically inert matrixmaterials and contribute to the cracking of high boiling cycle oilcomponents obtained in a reduced crude cracking operation. However,unlike cracking with an amorphous cracking catalyst, the ultra stablehydrogen form of zeolite herein discussed do the desired cracking orconversion of high molecular weight hydrocarbon components with asubstantial reduction in coke and gas production. This observeddifference in product selectivity when employing an ultrastablecrystalline zeolite in lieu of CREY for reduced crude cracking isunexpected and not previously predictable. Thus the cracking of highboiling residual oils comprising metallo-organic components boilingabove 1025° F. benefits in several significant ways herein identifiedwhen employing the ultrastable form of crystalline zeolites in catalystcompositions providing high surface area particle compositions.

It is, therefore, concluded that to more successfully crack high boilingrange feed stocks comprising residual oil of high Conradson carbon valueand to obtain desired product selectivity requires at least twofundamental operation conditions:

1. High regenerator temperatures which means a high catalyst temperatureat the point of oil catalyst contact.

2. A high surface area catalyst that can maintain a high surface areaexceeding that obtainable with CREY containing catalysts under theconditions of high, above 1400° F., regeneration temperatures.

A catalyst composition satisfying the above operating parameters andfound to be suitable for the specific conversion of high boilingresidual oil containing feed stocks is a catalyst comprising anultrastable crystalline zeolite as herein described. This particularcrystalline zeolite, sieve or crystalline aluminosilicate isindustrially referred to as an ultrastable sieve or crystalline zeolite.Compared to the state of the art rare earth exchanged zeolite (CREY)containing catalyst, the ultrastable sieve containing catalyst is of arelatively low activity but high surface area catalyst as measured inthe fresh catalyst state. This catalyst is described in various patentsbriefly referred to herein. The ultrastable zeolite containing catalystshave been discussed in the literature for application in the moreconventional clean feed gas oil cracking operations but because of itslow relative activity compared to rare earth containing zeolites andrelatively high cost has not received industry acceptance. However, ithas been found that when applied to residual oil cracking operations,the ultrastable zeolite catalyst becomes superior catalysts, byproviding and producing a profound improvement in cracking selectivityover the state of the art higher activity rare earth exchanged zeolitecontaining catalyst. This is illustrated in the commercial resultspresented in Table I, wherein cracking data is presented comparingperformance of the ultrastable sieve containing catalyst to a rare earthexchanged zeolite containing catalyst.

.Iadd.BRIEF DESCRIPTION OF THE DRAWING .Iaddend.

The drawing is a graphical representation of the contraction of anultrastable crystalline zeolite obtained during calcination underdifferent temperature conditions. It is observed that this contractionis substantially less than that obtained when subjecting a CREY catalystcomposition to similar conditions.

DISCUSSION OF SPECIFIC EMBODIMENTS

A class of zeolite containing catalysts particularly suitable for use inthe residual oil conversion process of this invention is one comprisingan ultra stable crystalline zeolite commercially identified as Z-14US.The preparation of an ultrastable crystalline zeolite discussed above isdescribed in U.S. Pat. No. 4,287,048, and referenced material includingU.S. Pat. Nos. 3,293,192 (1966) and 3,402,966, the subject matter ofwhich is incorporated herein by reference.

The ultrastable sieve or crystalline zeolite described in the aboveidentified referenced material and U.S. patents are characterized by asignificant (1-1.5%) decrease in the unit cell dimensions of the parentsodium zeolite. This contraction is caused by extraction of aluminumcations from the crystalline zeolite in the manufacturing process. Thishas been shown to be true by McDaniel and Maher in their book entitled"Zeolite Chemistry and Catalysis", page 320 by FIG. 17 and reproducedfor inclusion herewith as the drawing. In this drawing the shaded areaidentifies the unit cell contraction area for ultrastable zeolites ofdifferent silica to alumina ratio.

To be a suitable ultrastable crystalline zeolite component of thecatalyst for use in the process of this invention, the zeolite SiO₂ /Al₂O₃ ratio is greater than 3 and the unit cell size or lattice constant isless than 24.65 Angstroms. In particular embodiment, the ultrastablezeolite will have a SiO2/Al₂ O₃ ratio of at least 5 with a unit cellsize of about 24.5 Angstroms or less. A high sodium content zeolite,matrix components and residual oil feed are known to deactivate acracking catalysts zeolite crystalline structure relativity rapidly soit is important to reduce the sodium content of these materials andparticularly the finished zeolite sodium content to at least 1 weightpercent or less. Various techniques for achieving this low sodiumcontent are discussed in the literature. Preferably the residual Na₂ Oon the zeolite structure is below 0.5 weight percent.

The cracking activity level of an ultrastable crystalline zeolite isless than a rare earth exchanged zeolite such as CREY. Thus it requiresconsiderably more ultrastable zeolite than CREY to form catalystparticles of the same degree of activity. This high addition has beenconsidered heretofore as not suitable for use in hydrocarbon conversionoperations of lower regenerator temperatures.

Modern high activity FCC catalysts are reported to contain in the rangeof 15-40% of a rare earth type Y zeolite. In a conventional rare-earthzeolite catalyst employed in an FCC unit processing gas oils andoperating with regenerator temperatures generally maintained below 1400°F. and more usually not above 1350° F. or less requires using for thesame activity level an ultrastable crystalline zeolite catalystcomprising from 60-160% of the ultrastable zeolite. Obviously, nocatalyst could contain more than 100% of any component. A catalystparticle of such high zeolite content presents formidable problems tothe catalyst suppliers and manufacturer to produce such a catalystcomposition with suitable physical attrition resistant or hardnessproperties for use in a circulating fluid catalytic cracking system.

At relatively high regenerator temperatures in the range of 1350°F.-1600° F. and required in the high temperature conversion of residualoils an ultrastable crystalline zeolite catalyst obtained as aboveprovided is found to give an equilibrium activity that is equal to orexceeds that of a rare-earth type Y sieve (CREY) containing catalyst andprovides a higher equilibrium surface area without encounteringundesired coke and liquid product selectivity as herein identified. Ithas also been found that at a high oil feed--catalyst suspension mixtemperatures at least equal to the pseudo critical temperature of thefeed and characterized by regenerated catalyst temperatures at or above1350° F. the heavy or high boiling multi ring components in the oil feedare more readily converted thermally and catalytically to lower boilingdesired products by the high surface area ultrastable zeolite catalystin modern catalytic cracking facilities.

A commercial test of the ultrastable hydrogen form of crystallinezeolite containing catalyst herein identified provides the data shown inTable I. In this operation where the regenerator was operating over1400° F., the ultrastable zeolite containing catalyst actuallyout-performed a CREY catalyst. That is, lower coke yields were observedand there is a substantial drop in the heavy cycle oil yield and itsgravity. Extra light cycle oil and gasoline is produced at the expenseof coke and heavy cycle oil with liquid C₃ plus yield increasedsignificantly and all factors resulting in economic gain.

                  TABLE I                                                         ______________________________________                                        COMMERCIAL CRACKING PERFORMANCE                                               Type Zeolite in Catalyst*                                                                        Z-14US**   C--RE--Y                                        ______________________________________                                        CAT ADDN's #/Bbl. FEED                                                                           .34       .4                                               FEED RATE, B/D     18.070    18.000                                           FEED CON. CARBON, Wt. %                                                                          2.5       2.5                                              Rx. TEMP. °F.                                                                             982       974                                              REGEN. DENSE PHASE TEMP.                                                                         1.413     1.402                                            °F.                                                                    CONVERSION, VOL. % 80.8      80.1                                             C.sub.2 - YIELD, SCFB                                                                            312       324                                              ALKYL FEED, VOL. 5 (C.sub.3 -C.sub.4)                                                            26.7      26.1                                             GASOLINE, VOL. %   58.1      55.7                                             LCO, VOL. %        12.8      10.1                                             SLURRY, VOL. %     6.4       9.8                                              TOTAL LIQUID YIELD 104.0     101.7                                            C.sub.3 + VOL. %                                                              COKE, Wt. %        5.6       6.4                                              MICRO ACTIVITY     60        70                                               CATALYST SURFACE AREA                                                                            105       65                                               M.sup.2 /gm                                                                   ______________________________________                                         *Catalysts contained approximately same amount of zeolite promoter (Wt.       basis) when new.                                                              **Z14US refers to ultrastable zeolites.                                  

The reduction in heavy cycle oil product and increased light cycle oilproduct obtained as above-identified was surprisingly unexpected whencompared to the results obtained with a rare-earth exchanged crystallinezeolite (CREY) containing catalyst. Both forms of zeolite catalysts weresupported by a relatively inactive matrix material. The increase inequilibrium surface area indicates that substantially more zeolite ispresent in the equilibrium catalyst comprising the ultrastable hydrogenform zeolite containing catalyst.

                  TABLE II                                                        ______________________________________                                        Catalyst Sieve Type                                                                         US         RE--Y                                                Matrix Type   Low surface Area/Activity                                       Equil. S.A.   105        65                                                   ______________________________________                                    

The large surface area of the ultrastable zeolite is apparently veryeffective in providing active accessible cracking sites to cause theexperienced molecular weight reduction in the slurry oil. Unlikecracking with amorphous cracking catalysts, it is observed that theultrastable hydrogen zeolites do this cracking with less or a lower cokeand gas production. The data provided in Table I clearly indicates thatthe equilibrium activities of the two catalysts, ultrastable zeolite andrare earth exchanged zeolite, after exposure to regenerator temperaturesof about 1400° F., were quite similar in activity even though the CREYcatalyst started with 3-4 times the activity of the ultrastable zeolitecatalyst. At even higher regenerator temperatures, the benefits obtainedby using the ultrastable catalyst are expected to be even greater.

The following conclusions are reached in view of the above with respectto the fluid catalytic cracking of residual oil with an ultrastablecrystalline zeolite catalyst.

1. High catalyst temperatures at point of oil catalyst contact,vis-a-vis, high regenerator temperatures are necessary to morecompletely vaporize the high boiling residual oil feed stock.

2. Failure to adequately vaporize-atomize the feed encourages poorcracking selectivity i.e., encourages high coke make, high cycle oilproduction, particularly cycle oils rich in ring structures greater than2 member rings, high gas make and low gasoline production. The poorperformance attributed when the feed is inadequately vaporized is likelydue to the "coke shut off" of the active catalyst sites by the portionof the feed not vaporized.

3. As the residual oil content of the feed stock increases the catalysthigh temperature at point of oil contact (vis-a-vis high regeneratortemperature) must be permitted to rise to a higher optimum level inorder to encourage more nearly complete vaporization of the feed ifundesirable cracking selectivity is to be avoided.

4. Utilization of catalysts containing rare earth exchanged zeolites isinconsistent with high temperature regeneration despite their inherentrelatively high initial activity, because of rapid surface area decayand rapid loss of activity in high temperature regeneration environment.

5. Ultrastable sieve or crystalline zeolite containing catalysts despitetheir relatively low fresh catalyst activity equilibrate in a commercialcracking process when cracking residual oil at desired high temperatureconditions at acceptable catalyst activity levels and retain a desiredhigh surface area. This high surface area equilibrium leads to desirablecracking selectivity i.e., high yields of gasoline and gasoline formingcomponents, increased yields of cycle oils containing two member ringsproduced at the expense of cycle oils containing higher member ringswith substantially less coke make and a reduced gas production.

The ultrastable zeolite may be supported by any one of a differentmember of support materials or matrices. For example, matrices otherthan an inactive kaolin-clay silicon oxide binder combination can beused to hold or include the ultrastable hydrogen exchanged crystallinezeolite. In fact, any of the known prior art or conventional catalystmatrix materials can be used. Such materials would include syntheticsilica-alumina, clay, silica or alumina binders or any combinationthereof. The finished catalyst will preferably contain not less than 20wt % or more than 80% of an ultrastable hydrogen form of crystallinezeolite herein identified.

The ultrastable crystalline "Y" zeolite catalyst preferably employed bythis invention for cracking high boiling residual oils may be usedhowever, in conjunction with a metal entrapment material or metals sinkfor accumulation thereof. The finished catalyst will preferably containnot less than 20 wt % or more than 80% of an ultrastable hydrogen formof crystalline zeolite herein identified.

The catalytic cracking or conversion of high boiling hydrocarbonscomprising Conradson carbon producing materials are best catalyticallyconverted in a highly vaporized-atomized condition during contact withthe high surface area zeolite containing catalyst herein particularlydefined by employing contact temperature conditions provided by hotregenerated catalyst at least equal to the feed pseudo-criticaltemperature. Thus the catalyst regeneration temperature will increaseabove 1350° F. during combustion of deposited carbonaceous material asthe residual oil feed Conradson carbon value increases even though theultrastable zeolite catalyst composition employed in the conversionprocess of this invention contributes to a reduction in coke make. Thuswhen processing vacuum gas oils comprising the resid portion of thecrude oil, regeneration temperatures above 1350° F. and up to as high as1600° F. or more can be experienced as carbonaceous deposits increase inresponse to the feed Conradson carbon content.

The catalytic conversion operation of this invention is preferably oneof relatively short vaporized hydrocarbon contact with the specialcatalyst composition comprising from 20 to 80 wt % of ultrastablecrystalline zeolite as a dispersed catalyst phase in a riser contactzone wherein the hydrocarbon residence time in contact with catalystparticles can be restricted to within the range of 0.5 to 5 seconds andmore usually in the range of 1 to 3 seconds. This dispersed catalystphase-vaporized hydrocarbon contact may be implemented in substantialmeasure by the use of an atomizing diluent material with the highboiling hydrocarbon feed. Diluent materials suitable for this purposeinclude steam, CO₂, light normally gaseous hydrocarbons comprising C₃minus material or a combination thereof in an amount which will reducethe high boiling feed partial pressure and achieve desiredatomized-vaporized dispersion contact of hydrocarbon feed with hightemperature catalyst particles. Atomization of the feed may besubstantially implemented by use of appropriate spray nozzles. Thus theoperating parameters to achieve an optomized contact between feed andcatalyst particles also include feed exit velocities in excess of 10feet per second to achieve atomized spraying of the feed with or withoutdiluent material across a riser reactor cross section for intimatecontact with hot catalyst particles charged thereto.

The above identified operating parameters are intended to alsoaccelerate the mixture relatively uniformly within the feed vaporizationsection of a riser reactor in a minimum time frame and thus enhancerapid heat transfer from hot catalyst particles to charged feedpreferably atomized and thus prevent localized enhanced catalyst to oilratios contributing to a dense catalyst bed phase. That is, theoperating conditions and methods for implementing are selected to ensurea relatively dilute phase suspension contact between catalyst particlesand atomized oil feed for vaporized conversion transfer through a riserconversion zone. Such dilute catalyst phase operations include catalystparticle concentrations in the range of 2 to 10 pounds per cubic footand preferably not above about 5 pounds per cubic foot.

The catalyst hydrocarbon feed suspension formed as above provided ispassed through a riser contact zone for a hydrocarbon contact time lessthan about 5 seconds before discharge therefrom at a temperaturesufficiently elevated to maximize recovery of vaporized hydrocarbonmaterial separately from catalyst particles.

In a more particular and specific aspect the present invention isdirected to the catalytic conversion of high boiling residual oilscomprising vacuum gas oils containing high boiling Conradson carbonproducing materials employing a special ultrastable crystalline zeolitecontaining catalyst at a temperature equal to or above the feedpseudo-critical temperature in preferably a riser contact zone for ahydrocarbon residence time in the range of 0.5 to about 5 seconds andmore usually not above about 3 seconds.

Thus as the end boiling point of the hydrocarbon feed or the Conradsoncarbon level thereof increases so also will the catalyst regenerationtemperature generally increased in response to increased depositedcarbonaceous material removed by combustion and contributing to hightemperature regeneration and conversion of the feed according to theconcepts of this invention. However, as discussed above, employing theultrastable zeolite catalyst provides a lower coke yield than obtainedwith the rare earth zeolite catalyst thus contributing measurably to theadvantages of the processing concepts of this invention as hereindescribed.

Depending on the feed hydrocarbon to be converted, its boiling range andConradson carbon contributing factor, the hydrocarbon conversionoperation may be effected at a temperature in the range of 950° F. up toabout 1400° F. or at a temperature equal to or above the feedpseudo-critical temperature employing a reactor pressure from aboutatmospheric pressure up to about 100 psig but generally not above about50 psig.

The riser cracking operation of this invention may be employed inconjunction with the catalyst regeneration arrangement of copendingapplication Ser. No. 169,086, filed July 15, 1980 (now U.S. Pat. No.4,332,674), the subject matter of which is incorporated herein byreference thereto. That is, the apparatus and operating concepts of theabove identified application and the methods of implementation except asparticularly modified by employing an ultrastable crystalline zeolitecontaining catalyst, as herein provided, may be employed withconsiderable advantage in protecting the activity and selectivitycharacteristics of the ultrastable crystalline zeolite catalystparticularly when reducing residual coke on the ultrastable zeolitecatalyst to less than about 0.25 wt. %.

Having thus generally described the method and concepts of thisinvention and discussion specific embodiments in support thereof, it isto be understood that no undue restrictions are to be imposed by reasonsthereof except as defined by the following claims.

We claim:
 1. A method for .[.upgrading.]. .Iadd.increasing conversion toliquid products of .Iaddend.a residual oil portion of crude oil boilingabove 600° F. comprising metallo-organic compounds which comprisescontacting .Iadd.a feed containing .Iaddend.said residual portion ofcrude oil boiling above 600° F. .Iadd.said feed having a Conradsoncarbon content above about 2.5 weight percent .Iaddend.with a catalystconsisting of from 20 to 80 wt. % of an ultrastable faujasitecrystalline zeolite dispersed in a .[.silica-clay.]. matrix .[.for atime at a temperature particularly selective for conversion of theresidual portion of crude oil to products of gasoline, light cycle oiland gasoline forming gaseous components, andrecovering said productscomprising gasoline and light cycle oil.]. .Iadd.selected from the groupconsisting of: silica-clay, silica-alumina, clay, silica, alumina andmixtures thereof, at a temperature above about 950° F. to provide aratio of volume percent of light cycle oil to heavy cycle oil of inexcess of 1.03 at essentially constant conversion and recover said lightcycle oil and heavy cycle oil .Iaddend..
 2. The method of claim 1wherein the .Iadd.light .Iaddend.cycle oil comprises two member ringsproduced at the expense of producing of cycle oils of higher memberrings.
 3. The method of claim 1 wherein the ultrastable faujasitezeolite .Iadd.is .Iaddend.of a pv 0.5-3 microns size .[.is distributedin a matrix material selected from; a kaolin clay-silicon oxide bindermaterial; silica-alumina, clay, silica, alumina and a high surface areaamorphous material providing active cracking sites.]..
 4. The method ofclaim 1 wherein the catalyst comprises the ultrastable faujasitecrystalline zeolite in an amount within the range of 30 to 50 wt. %. 5.The method of claim 1 wherein the ultrastable crystalline zeolitecomponent of the catalyst is prepared under conditions to provide a highsurface area material, a silica/alumina ratio of at least 3 and a unitcell size less than 24.65 Angstroms.
 6. The method of claim 1 whereinconversion of the residual portion of the crude oil is accomplished fora time less than 3 seconds at an elevated temperature sufficient toachieve substantially instantaneous vaporization of the charged residualoil in atomized condition upon contact with high temperature catalystparticles.
 7. The method of claim 6 wherein the temperature of thecatalyst is at least equal to the feed pseudo-critical temperature andresidual oil feed comprises metalloorganic components boiling above1025° F.
 8. The method of claim .[.7.]. .Iadd.6 .Iaddend.wherein .[.thecatalyst elevated.]. .Iadd.said high .Iaddend.temperature .Iadd.of saidcatalyst particles is .Iaddend.achieved by burning hydrocarbonaceousdeposits of said residual oil conversion .Iadd.and .Iaddend.increases inresponse to the feed Conradson carbon content at catalyst regenerationtemperatures in the range of 1350° to 1600° F.
 9. The method of claim 1wherein the ultrastable faujasite crystalline zeolite is prepared toprovide high surface area zeolite with a silica/alumina ratio of atleast 5 and a unit cell size of about 24.5 Angstroms or less.
 10. Themethod of claim 1 wherein an atomizing diluent material is used with theresidual oil feed comprising one or more materials selected from steam,CO₂, light normally gaseous hydrocarbons comprising C₃ minus materialsin cooperation with atomizing spray nozzles.
 11. The method of claim 10wherein the conditions are selected to insure a relatively dilute phasesuspension contact between catalyst particles and atomized oil feed forvaporized conversion transfer through a riser conversion zone as aparticle concentration in the range of 2 to 10 pounds per cubic foot anda vapor residence time within the range of 0.5 to 3 seconds.
 12. Themethod of claim 1 wherein the residual oil portion of crude oilcomprises high boiling Conradson carbon producing materials and metalcontaminants.
 13. The method of claim 1 wherein the residual oilconversion operation is effected at a temperature in the range of about950° F. up to about 1400° F. and at a temperature equal to or above thefeed pseudo-critical temperature.
 14. A method for catalyticallyconverting residual oils comprising vacuum bottoms whichcomprises,converting said residual oil with a catalyst consisting ofabout 30-50 wt. % of ultrastable faujasite crystalline zeolite dispersedin a matrix material of clay and silica binder providing active crackingsites, said catalytic conversion effected at said residual oilpseudo-critical temperature for a time in the range of 0.5 to 3 secondsin a riser reaction zone, and recovering a product selectively of saidcatalytic conversion particularly comprising gasoline and light cycleoils comprising largely two member rings separately from catalystparticles comprising hydrocarbonaceous deposits of said conversion. 15.The method of claim 14 wherein the separated catalyst comprisinghydrocarbonaceous deposits is regenerated in a sequence of separatecatalyst regeneration zones of increasing temperatures in the directionof catalyst flow permitting effecting the residual oil conversion at atemperature in the range of 950° to 1400° F.
 16. The method of claim 15wherein the sequence of catalyst regeneration steps removes residualcarbon on the catalyst to below 0.25 wt. %.
 17. The method of claim 14wherein the zeolite comprises less than 0.5 wt. % Na₂ O and a highersurface area than a rare earth exchanged faujasite crystalline zeolite..Iadd.18. The method of claim 1 wherein said catalyst is regenerated ata temperature above about 1350° F. .Iaddend. .Iadd.19. The method ofclaim 18 wherein said matrix consists of kaolin clay and silica..Iaddend. .Iadd.20. The method of claim 1 wherein said contacting timeis less than 5 seconds and said temperature for conversion is in therange of 950° F. to about 1400° F. .Iaddend. .Iadd.21. The method ofclaim 1 wherein said matrix has active cracking sites. .Iaddend..Iadd.22. A method for increasing conversion to liquid products of aresidual oil portion of crude oil feed boiling above 600° F. said methodcomprising:(a) contacting said feed having a Conradson carbon contentabove about 2.5 weight percent with a catalyst consisting of from 20 to80 wt. % of an ultrastable Y zeolite dispersed in a matrix saidcontacting (i) providing an increase in production of light cycle oilrelative to heavy cycle oil to provide a ratio of volume percent of saidlight cycle oil to said heavy cycle oil in excess of 1.03 at essentiallyconstant conversion and (ii) producing carbonaceous deposits on saidcatalyst; and (b) regenerating said catalyst by combusting saidcarbonaceous deposits in the substantial absence of hydrothermaldeactivation of said catalyst wherein at least a portion of saidregeneration occurs at a temperature of at least about 1350° F..Iaddend. .Iadd.23. The method of claim 22 wherein said matrix isselected from the group consisting of silica-clay, silica-alumina, clay,silica, alumina, and mixtures thereof. .Iaddend. .Iadd.24. The method ofclaim 22 wherein said residual oil portion comprises components boilingabove 1050° F. .Iaddend. .Iadd.25. The method of claim 24 wherein atleast a portion of said regenerating is accomplished at a regeneratortemperature of between about 1350° F. and about 1600° F. .Iaddend..Iadd.26. The method of claim 11 wherein said ultrastable Y zeolite hasa silica/alumina ratio of at least 3 and a unit cell size less than24.65 Angstroms. .Iaddend. .Iadd.27. The method of claim 22 wherein adiluent material is used with the residual oil portion said diluentmaterial comprising a material selected from the group consisting ofsteam, CO₂, light normally gaseous hydrocarbons comprising C₃ minusmaterials, and mixtures thereof in cooperation with spray nozzles..Iaddend. .Iadd.28. The method of claim 22 wherein said regeneratingremoves said carbonaceous deposits on said catalyst to below about 0.25weight percent. .Iaddend. .Iadd.29. The method of claim 23 wherein saidmatrix has active cracking sites. .Iaddend. .Iadd.30. The method ofclaim 22 wherein said contacting of the residual oil and catalyst iseffected at a temperature in the range of about 950° F. to about 1400°F. .Iaddend. .Iadd.31. The method of claim 22, wherein said contactingof the residual oil and catalyst is effected at a temperature equal toor above the crude oil pseudo-critical temperature. .Iaddend. .Iadd.32.In a method for upgrading an oil feed containing residual oil boilingabove 600° F. wherein said residual oil is contacted with a crackingcatalyst the improvement comprising:providing an increase in productionof light cycle oil compared to heavy cycle oil and yield a ratio volumepercent of light cycle oil to heavy cycle oil in excess of about 1.03 atessentially constant conversion and an increase in conversion to C₃ andheavier liquid products by contacting said residual oil with a catalystwhich maintains an equilibrium surface area in excess of 65 m² /gmwherein said catalyst comprises 20 to 80 wt. % ultrastable Y zeolite ona matrix and recovering said light cycle oil and heavy cycle oil..Iaddend. .Iadd.33. The method of claim 32 wherein carbonaceous depositsare formed on said catalyst by contacting said residual oil and saidcatalyst containing said deposits is regenerated by combusting saidcarbonaceous deposits at a temperature of at least about 1350° F. andwherein said equilibrium surface area is at least about 105 m² /gm..Iaddend. .Iadd.34. The method of claim 32 wherein said catalyst iscontacted with said residual oil at a temperature of at least about 950°F. .Iaddend. .Iadd.35. The method of claim 32 wherein said matrix isselected from the group consisting of silica-clay, silica-alumina, clay,silica, alumina and mixtures thereof. .Iaddend. .Iadd.36. The method ofclaim 35 wherein said matrix has active cracking sites. .Iaddend..Iadd.37. The method of claim 35 wherein carbonaceous deposits found onsaid catalyst when said catalyst contacts said residual oil arecombusted at a temperature of at least about 1350° F. to provide aregenerated catalyst. .Iaddend. .Iadd.38. The method of claim 35 whereinsaid catalyst is contacted with said residual oil at a temperature equalto or above the pseudo-critical temperature of said crude oil. .Iaddend..Iadd.39. The method of claim 32 wherein said contacting is effected ata temperature between about 950° F. and 1400° F. and producescarbonaceous deposits on said catalyst, said catalyst containing saiddeposits being regenerated by combusting said deposits to provide aregeneration temperature in the range of about 1350° F. to 1600° F..Iaddend. .Iadd.40. The method of claim 39 wherein said regenerationtemperature is at least about 1400° F. .Iaddend. .Iadd.41. The method ofclaim 22 wherein at least a portion of said regeneration occurs at atemperature of at least about 1400° F. .Iaddend.